Improvement in the process of protecting iron from oxidation



UNITED STATES PATENT OFFICE.

PALMER SUMNER AND PETER NAYLOR, OF NEW YORK, N. Y.

IMPROVEMENT IN THE PROCESS OF PROTECTING lRON FROM OXIDATION.

Specification forming part of Letters Patent 'No. [,374, dated October18, 1839.

To all whom it may concern:

Be it known that we, PALMER SUMNER and PETER NAYLOR, of the city of NewYork, in the State of New York, have invented an improvement in theprocess, method, or methods by which various articles of iron or steelmay be preserved from oxidation or rusting by the galvanic actionproduced by zinc, (for which process Lei tcrs Patentwere granted to M.Sorel on the 7th day of December, 1837 and we do hereby declare that thefollowing is a full and exact description of our improvement.

We, the said PALMER SUMNER and PETER NAYLOR, having become proprietors,by assignment, of a right to use the said process, have, in carrying thesame into practical op eration, found the malleability of sheet-ironismuch impaired by giving thereto a coating of zinc in the manner directedin the specification of the Letters Patent of said M. Sore], and that inconsequence of this diminished malleability such prepared sheet-iron isunsuited in many cases to be applied to the purpose of covering theroofs of houses, or to be otherwise used where it is required to begrooved, seamed, or in any way suddenly bent; and our improvementconsists in a process by which this difficulty is obviated, while thezinc is at the same time so applied as, by its galvanic action on theiron, to protect it from oxidation.

. We take sheets of iron and cover them with tin or with an alloy of tinand lead, adopting in this process the mode or modes followed in thewell-known manufacture of sheets or plates of iron into tin-plate Afterhaving completed this operation we submit the sheets or plates soprepared to a like process, with the substitution of zinc for tin or analloy of tin, the mode of performing which process is fully set forth inthe Letters Patent granted to said M. Sore], and does not dider from theordinary process known under the name of tinning. When thus treated theplates or sheets of iron preserve their malleability unimpaired, and maybe bent and otherwise worked as easily as before they had received suchcoating-a result which appears to be due to theinterposition of thecoatingof tin between the zinc and the iron, by which interposition thechemical combination of the iron and zinc is prevented. Where it is notnecessary to use plates of metal of a larger size than that of sheets oftin-plate we take that material as it comes from the manufactories, andhave then only to give to it a coating of zinc, to receive which it doesnot require any particular. preparation.

In the Letters Patent granted to M. Sorel it is proposed sometimes toadd a coating of tin over that of the zine for the purpose of giving tothe article made a bright appearance, and as an improvement also inculinary vessels; but our process is the reverse of this, and the endattained by us altogether different from that above proposed, and at thesame time our process produces a new and useful result.

What we claim, therefore, as our invention, and as an improvement on theprocess of ill. Sorel, is-

1. The preserving the mallcability ofsheetiron while it is protectedfrom oxidation by the galvanic action between it and zinc, in the mannerherein set forth-namely, by first tinning said iron in the ordinary wayand afterward by giving thereto a coating of zinc above the tin.

2. The protection of iron and manufactures of iron generally from rustby the same process.

PALMER SUMNER. PETER NAYLOR.

Witnesses:

K. S. VAN VooEHis, GEo. STEVENs.

